Keeping Track of the Atmosphere…

GEOmon is a European funded project which aims to quantify and understand on-going changes in the atmosphere through systematic observations of long-lived greenhouse gases, reactive gases, aerosols and stratospheric ozone.

GEOmon efforts are in the areas of:

Data Collection

Data Storage and Availability

Data Analysis and Modeling

Communication of results

1. Data Collection

GEOmon measures the levels of carbon dioxide(CO2), methane (CH4), ozone (O3), in the atmosphere as well as the quantity of aerosols (suspension of fine solid particles or liquid droplets in air), wind speed, temperature and other meterological conditions.

Ground-Based Measurements

Measurements are carried out by at observation stations throughout the world using upward-looking, ground-based remote sensing instruments including:

Max-DOAS (Multi Axis Differential Optical Absorption Spectroscopy) instruments. These instruments are basically UV/visible spectrometers observing scattered light in different viewing directions. As the radiation passes through the atmosphere certain wavelengths are absorbed by different trace gases. The amount of trace gases can be calculated through the change in absorption at different times of day, knowing the different path lengths that this radiation has taken through the atmosphere.

FTIR-spectrometers (Fourier Transform Infra-Red) Solar radiation is collected by the solar tracker and directed to FTIR-spectrometer within which the radiation is split into two beams, which travel separate paths through the instrument and are then recombined. The length of one path is varied with respect to the other. Information about trace gases is retrieved by fitting a computer-simulated spectrum to the recorded one.

LIDAR (Light Detection and Ranging) Lidar works by transmitting laser signals using all light ranges (ultraviolet, visible, infrared) and amplifying the light that is scattered back through an optical telescope and photomultiplier tube.

Tropospheric/ Stratospheric Measurements by Aircraft

Measurements carried out by commercial aircraft in a related scientific project, CARIBIC, also add to our understanding of the composition of the atmosphere and its physical transport properties. Much of the sampling occurs at altitudes of 10-12 km which is at the limit between the troposphere and the stratosphere (the tropopause). This gives us information about the chemistry and transport mechanisms in a little-documented region that is of significant importance.

These measurements allow us to validate, calibrate and better understand the broad picture provided by satellite data.

2. Data Storage and Availability

Data is transmitted, in near real-time for many stations, to a common Data Centre. The objective for GEOmon is to integrate large volumes of diverse data from many different sources into an access structure that enables the scientific community, resource management and policymakers to freely and easily obtain this information.

3. Data Analysis and Modeling

Various models will be applied to the observed data to simulate atmospheric chemistry and to produce 4D (four-dimensional) climatologies. This will in turn contribute to our knowledge of future climate evolutions.

4. Communication of results

It is essential that the work of the GEOmon scientists be communicated at all levels of society in order to contribute to a better understanding of climate change, the greatest challenge facing mankind. This means communicating in a appropriate and adapted way to the broader scientific community, resource providers, policy-makers and the general public.

The GEOmon Blog

The scientists working within the GEOmon project are geographically dispersed throughout the world. They contribute to this blog in an effort to communicate with each other and the world at large about the field of climate science.